If you are willing to buy business domains and hosting online, then GoDaddy is one of the best options. You can simply log in to the GoDaddy account by following these instructions:
1) Open your web browser.
2) Go to the GoDaddy official website
3) Enter your credentials. (username and password)
4) Click on the login button. 
You will be successfully logged in to your GoDaddy account.
For more information: https://worldzo.net/godaddy-webmail-login/